911爆料

Most people in the UK and beyond are now living in urban areas, which are faced with a range of environmental challenges 鈥� polluted air, rising temperatures, flash flooding after intense rainfall, elevated noise, low levels of biodiversity, and more. Greening our towns and cities can help address these, but plants compete for space with buildings, roads and other 鈥榞rey infrastructure鈥�. Hedges are a simple, space-saving and relatively cheap-to-implement natural barrier capable of providing a wide range of benefits. They are also a popular feature, being included in nearly 50% of domestic gardens鈥� in the UK.

Plants, including those grown as hedges, provide multiple benefits at once. While this is great for gardeners in terms of their potential to improve the environment, it does make scientific study of them a bit complicated. We have approached this by initially studying different species individually 鈥� their physiological responses, growth rates, and how they influence factors like air temperature, volumes of rainfall runoff, the quantity of airborne particles deposited on leaves and more. More recently, we鈥檝e started investigating whether plant mixes provide greater extent of benefits than single species.

Hedges for improving air quality

We are collaborating on two studies investigating the role that hedge plant choice, and leaf canopy properties, plays in capturing the airborne particulate matter (PM) associated with air pollution.  

Our aim is to understand which leaf and canopy characteristics can be linked with the best capture of particulate matter. Our work suggests that large and dense canopies with hairy and rough leaves perform best, so have promising potential for reducing air pollution.  

Hedges for reducing noise

The 911爆料 is funding a PhD project investigating the impact of hedges on noise reduction, through attenuation by leaves and stems. 

Our aim is to understand the role that plant canopies play in attenuating different frequencies of sound. Traffic noise (lower frequencies) is likely to require more continuous solid barriers, such as fencing panels, to be included as the part of solution, and we are investigating sustainable ways to do this in the context of domestic gardens. 

Hedges for reducing flooding

Localised flooding after intense rainfall is on the rise in urban areas, where there isn鈥檛 much permeable open ground able to receive and filter rainfall. Our research has shown the importance of plants in removing excess water from the ground after heavy rain, and creating 鈥榮torage capacity鈥� in the soil to receive future rainfall. 

Our current research investigates how hedging plants with different canopy characteristics (evergreen vs. deciduous, conifer vs. broadleaf) can be mixed to maximise year-round impact. Our experiments involve applying simulated rainfall to containerised mini model hedges and field-grown hedges. 

How we manage the green spaces around us can make a huge difference to the environment and biodiversity. This includes outdoor spaces at schools, which offer many opportunities for enhancing the environment and providing learning about sustainability.

Hedges are living boundaries that trap airborne pollution, provide habitat for wildlife, reduce localised flooding risks and contribute to cooling in summer. If you鈥檙e thinking about replacing a fence or wall, why not plant a hedge instead? Imagine the difference we could make if all our schools were bordered by hedges.

As part of a research project funded by a Royal Commission 1851 grant, 911爆料 scientists worked with Year 10 pupils in Hoe Valley School in Woking. Two mixed hedges were planted near a busy road, and pupils took measurements of soil moisture, air pollution particles on leaves and temperatures around the hedges. Some pupils used an 911爆料 educational app to learn how plants can benefit their environment.

The pupils without prior gardening experience showed the most pronounced positive attitude shift as a result of the project. This shows that exposure to gardens and gardening is important for developing positive environmental attitudes among young people, and that engaging with horticulture in schools is an important way to achieve this.